<template>
	<view>
		<!-- 搜索组件 -->
		<my-search bg-color="#C00000" :border-radius="16" @click="goSearch"></my-search>
		<view class="scroll-view-container">
			<!-- 左侧的滚动视图区域 -->
			<scroll-view class="left-scroll-view" scroll-y :style="{height: wh + 'px'}">
				<view @click="tabChange(index)"
					:class="index===activeIndex ? 'left-scroll-view-item active':'left-scroll-view-item' "
					v-for="(item,index) in cateList" :key="index">{{item.cat_name}}</view>
			</scroll-view>
			<!-- 右侧的滚动视图区域 -->
			<scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px'}" :scroll-top="scrollTop">
				<view class="cate-lv2" v-for="(item2, i2) in rightList" :key="i2">
					<view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
					<!-- 动态渲染三级分类的列表数据 -->
					<view class="cate-lv3-list">
						<!-- 三级分类 Item 项 -->
						<view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="goList(item3)">
							<!-- 图片 -->
							<image :src="item3.cat_icon"></image>
							<!-- 文本 -->
							<text>{{item3.cat_name}}</text>
						</view>
					</view>
				</view>
			</scroll-view>
		</view>
	</view>
</template>

<script>
	import badgeMix from '@/mixins/tabbar-badge.js'
	export default {
		mixins:[badgeMix],
		data() {
			return {
				// 高度
				wh: 0,
				// 分类数据
				cateList: [],
				// 激活项
				activeIndex: 0,
				// 右侧数据
				rightList: [],
				 // 滚动条距离顶部的距离
				    scrollTop: 0
			};
		},
		onLoad() {
			// 获取当前系统的信息
			const sysInfo = uni.getSystemInfoSync()
			// 为 wh 窗口可用高度动态赋值
			this.wh = sysInfo.windowHeight - 50
			// 获取数据
			this.getCateList()
		},
		methods: {
			// 请求数据赋值
			async getCateList() {
				const {
					data: res
				} = await uni.$http.get('/api/public/v1/categories')
				if (res.meta.status !== 200) return uni.$showToast()
				this.cateList = res.message
				this.rightList = this.cateList[0].children
			},
			// 左侧点击事件
			tabChange(idx) {
				this.activeIndex = idx
				this.rightList = this.cateList[idx].children
				// 要scrollTop 重置 （只要让scrollTop变化即可）
				this.scrollTop = this.scrollTop ? 0 : 1
			},
			// 跳转到搜索页
			goSearch(){
				uni.navigateTo({
					url:'/subpkg/search/search'
				})
			},
			// 跳转到列表页面
			goList(val){
				uni.navigateTo({
					url:'/subpkg/goods_list/goods_list?cid='+val.cat_id
				})
			}
		}
	}
</script>

<style lang="scss">
	.scroll-view-container {
		display: flex;

		.left-scroll-view {
			width: 120px;

			.left-scroll-view-item {
				line-height: 60px;
				background-color: #f7f7f7;
				text-align: center;
				font-size: 12px;

				// 激活项的样式
				&.active {
					background-color: #ffffff;
					position: relative;

					// 渲染激活项左侧的红色指示边线
					&::before {
						content: ' ';
						display: block;
						width: 3px;
						height: 30px;
						background-color: #c00000;
						position: absolute;
						left: 0;
						top: 50%;
						transform: translateY(-50%);
					}
				}
			}
		}

		.cate-lv2-title {
			font-size: 12px;
			font-weight: bold;
			text-align: center;
			padding: 15px 0;
		}
		.cate-lv3-list {
		  display: flex;
		  flex-wrap: wrap;
		
		  .cate-lv3-item {
		    width: 33.33%;
		    margin-bottom: 10px;
		    display: flex;
		    flex-direction: column;
		    align-items: center;
		
		    image {
		      width: 60px;
		      height: 60px;
		    }
		
		    text {
		      font-size: 12px;
		    }
		  }
		}
	}
</style>
